The Air You Breathe Is Loaded With Microbes

Study to help measure changes in airborne bacteria populations.

The air you breathe is teeming with more than 1,800 kinds of bacteria, including harmless relatives of microbes associated with bioterrorist attacks, according to a new study.

The finding, detailed online in December 2006 in the journal for the Proceedings of the National Academy of Sciences, would allow scientists to create a baseline against which future researchers can measure changes in bacterial populations due to factors such as climate change. Plus, by knowing what’s typically aloft in the air, scientists could distinguish between normal and suspicious fluctuations — a sign of a bioterrorist attack.